i just recently bought a '91 Z-28 there was a problem with the system draining batteries, with a new alternator and battery installed, we fixed a loose ignition wire on the starter to take care of that, now while driving the guages will suddenly burry themselves and quit working and the engine will run rough, then it will smooth out and run fine with the guages working correctly also, and back and forth. just now it is staying messed up, doesn't seem to be going back and forth. any suggestions? i'm figuring bad ground somewhere, but there are so many